1. Technical Field
This invention relates to power-train torque demand control for controlling a gear ratio of an automatic transmission and an operation of an internal combustion engine on the basis of a target vehicle drive force.
2. Related Art
A method of controlling an output of an internal combustion engine on the basis of a depression amount of an accelerator pedal and controlling a gear ratio of an automatic transmission on the basis of the depression amount of the accelerator pedal and a vehicle speed is widely employed as a conventional method of controlling a drive force of a vehicle. In this method, the engine and the transmission are controlled independently in accordance with respective individual target values.
Meanwhile, JP2001-328462A, published by the Japan Patent Office in 2001, proposes power-train torque demand (PTD) control in which a target vehicle drive force is set on the basis of an accelerator pedal depression amount and a vehicle speed, whereupon a gear ratio of an automatic transmission and a torque of an internal combustion engine are controlled in an integrated fashion so that the target vehicle drive force is obtained.